1. Field of the Invention
The present invention relates to parts washers and, more particularly, to a parts washer for collecting either wet or just moist sludge in a removable tank.
2. Description of Related Art
Parts washers have been available for decades for cleaning parts of contaminants, dirt, grease, combinations thereof, etc. One field in which such parts washers are used extensively is that in automotive repair facilities where dirty or contaminated parts are cleaned for disassembly and/or assembly. Parts washers of this type are also used in many other industries.
As set forth in U.S. Pat. No. 3,707,404, a conventional parts washer includes a tank having a cleaning solvent floating upon a more dense fluid, such as water. A basin, located above the tank and wherein the parts are washed, includes a drain extending downwardly into the water. A pump pumps the solvent upwardly for discharge into the basin to accommodate washing/scrubbing of the parts with the solvent. The solvent drains through the drain into the water due to the pressure head of solvent developed in the drain. Solvent and entrained contaminants discharge from the drain into the water and the solvent percolates upwardly while the contaminants are segregated from the solvent and sink to the bottom of the tank. An outlet at the bottom of the tank permits periodic drainage of the sludge and water.
Because the sludge in the tank tends to become packed, it will not readily drain and may collect for a period of years. Where the sludge is toxic and corrosive, the bottom of the tank may deteriorate to the extent of creating a health hazard due to leakage of the sludge. Under present safety regulations, disposal of waste water containing toxic sludge is significantly more expensive than the costs attendant disposal of only moist toxic sludge. To empty the sludge from the tank through a drain requires unnecessary handling and creates potential safety hazards as well as incurring additional costs.